If log321, log323, log329, log3227 ........... is a sequence, the sum of its first five terms islog3222log3247log32121log32107

The given sequence is a logarithmic sequence where the base is 3 and the numbers are 21, 23, 29, 27, and so on.

The sum of the first five terms of this sequence can be calculated using the properties of logarithms.

Step 1: Write down the first five terms of the sequence:

log3(21), log3(23), log3(29), log3(27), log3(121)

Step 2: Use the property of logarithms that states the sum of the logs is equal to the log of the product of the numbers:

log3(21) + log3(23) + log3(29) + log3(27) + log3(121) = log3(21232927121)

Step 3: Calculate the product of the numbers:

21232927121 = 210766807

Step 4: Substitute the product back into the logarithm:

log3(210766807)

So, the sum of the first five terms of the sequence is log3(210766807).